As mobile devices proliferate, the demand for services tailored to device location also increases. Location-based services depend on positioning systems to determine device location. Satellite-based position systems, such as the global positioning system (GPS), GLONASS, and Galileo can provide high accuracy, but require a clear line of sight between the satellites and the mobile device to provide a position determination. Consequently, satellite-positioning systems are largely ineffective for indoor positioning. Satellite positioning also requires specialized receivers that may increase the cost of the mobile device.
As an alternative or an augmentation to satellite based positioning, wireless local area network (WLAN) based positioning systems have been developed. WLAN based positioning systems are suitable for indoor positioning and require minimal investment because they make use of existing infrastructure. Furthermore, many mobile wireless devices include support for communication via WLAN. WLAN-based positioning systems determine mobile device position based on the established positions of WLAN access points visible to the device and the strength of signals exchanged between the mobile device and the access points.